On Mon, Nov 12, 2018 at 08:58:24PM -0800, Nicolin Chen wrote: > Hi Guenter, > > On Mon, Nov 12, 2018 at 08:32:48PM -0800, Guenter Roeck wrote: > > On Mon, Nov 12, 2018 at 08:23:53PM -0800, Nicolin Chen wrote: > > > INA3221 supports both continuous and single-shot modes. When > > > running in the continuous mode, it keeps measuring the inputs > > > and converting them to the data register even if there are no > > > users reading the data out. In this use case, this could be a > > > power waste. > > > > > > So this patch adds a single-shot mode support so that ina3221 > > > could do measurement and conversion only if users trigger it, > > > depending on the use case where it only needs to poll data in > > > a lower frequency. > > > > > > The change also exposes "mode" and "available_modes" nodes to > > > allow users to switch between two operating modes. > > > > > Lots and lots of complexity for little gain. Sorry, I don't see > > the point of this change. > > The chip is causing considerable power waste on battery-powered > devices so we typically use it running in the single-shot mode. > And you need to be able to do that with a sysfs attribute ? Are you planning to have some code switching back and forth between the modes ? You'll need to provide a good rationale why this needs to be runtime configurable. Guenter > Although the chip now can be powered down, but we still need to > occasionally poll it for power measurement and critical alerts, > so single-shot mode is the best choice for us, considering that > the power-down-and-up routine would be way heavier. > > I could understand that you don't really like it, but it's some > feature that we truly need. Do you have any suggestion to write > the code that can make it more convincing to you? > > Thanks > Nicolin
